Hosting an exit node is not illegal (in the United States), and generally you cannot be held liable if the network was used for illegal actions as a consequence of being an exit node and not committed by you (this is not legal advice); however, you have to be able to prove that and it does not necessarily mean you are protected from being investigated, having your door kicked in, and/or your equipment seized.
> being investigated, having your door kicked in, and/or your equipment seized.
True and good to be aware of (upvoted), but I think it is fair to note that this is a very small number of cases. It's not small odds like "win the lottery" odds, but it's also not likely that it'll happen to you. Definitely something to be aware of and plan for (e.g. don't also use that server for important stuff, say, your email and website).
